jq index()

$(selector).index(element)

    <ul class="indextest">
		<li>
			<div>0</div>
		</li>
		<li>
			<div>1</div>
		</li>
		<li>
			<div>2</div>
		</li>
		<li>
			<div>3</div>
		</li>
		<li>
			<div>4</div>
		</li>
	</ul>

　　

$('.indextest div').click(function(event) {
	/* Act on the event */
	console.log($(this).index('.indextest div'));
});